Punch and die mechanism for forming sharp corners in wave guides



May 20, 1958 F. J. FUCHS, JR., ETAL 2,835,151

PUNCH AND DIE MECHANISM FOR FORMING SHARP coRNERs 1N WAVE GUIDES 4 Sheets-sheet 1 Filed June 28, 1955 ATTORNEY 4 Sheets-Sheet 2 May 20, 1958 F. J. FucHs, JR.. E'rAL PUNCH AND DIE MECHANISM FOR FORMING -coRNERs 1N WAVE VGUIDES Filed June 28, 1955 May 20, 1958 F. J. FUCHS, JR., ETAL 2,835,151

PUNCH AND DIE MECHANISM FOR FORMING SHARP CORNERS IN WAVE GUIDES Filed June 28, 1955 4 Sheets-Sheet 3 '5?' Zf /77 INVENToR i; f, Wi/ FRANCIS J.Fuc|ls,J|: 'nl l/ l f' RALPH C.TAY| 0R 35 t/ f f/ Jg; 5 g3g, BY l ATTORNEY May 20, 1958 F. J. FUcHs, JR., ETAL 2,835,151

PUNCH AND DIE MECHANISM FOR FORMING SHARP CORNERS IN WAVE GUIDES Filed June 2s, 1955 4 Sheets-Sheet 4 //f INVENTORS FRANCISAJ. FucHs,Jr., RALPH c. TAYLOR,

United, States Patent O PUNCH AND DIE MECHANISM FOR FORMING SHARP CORNERS IN WAVE GUIDES Francis J. Fuchs, Jr., and Ralph C. Taylor, Winston- Salem, N. C., assignors to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York t Application .lune 28, 1955, Serial No. 518,524

11 Claims. (Cl. 78--60) order to divide an electromagnetic wave being propagated along the vertical or leg member of the T and cause the divided wave to be propagated in halves in opposite directions along the horizontal or cross member of the T. inasmuch as electromagnetic waves which are propagated in this manner travel along such conductors in a relatively thin skin of the metal Walls defining the bores of the tubes, it is essential that the interior dimen-` sions of the various tube sections and joints be maintained as closely as possible to predetermined configurations in order to eliminate mechanical imperfections which would result in undesirable variations in the electromagnetic transmission characteristics of the tube sections or joints. In order to eiiect the above-mentioned division of the electromagnetic wave it is necessary that a sharply pointed indentation be formed in the horizontal or cross member of the 'lshaped joint in the side of the` cross member opposite to that which intersects the leg member of the T-shaped joint. This indentation must conform to the theoretical configuration to avoid distortion as the wave is divided.

Prior to this invention a common procedure for constructing joints of this type was to machine the joint from a piece or pieces of solid stock. Another method was to cast the joint in one or more pieces and subsequently machine the `piece or pieces. Obviously, both these methods require the expenditure of considerable time and energy to perform the necessary machining perations and hence are quite costly. lt can be seen, therefore, that considerable expense could be eliminated if it were possible to form the indentation necessary for this type of joint in a standard piece of wave guide tubing in one forming operation and thus eliminate many machining operations. ln order to perform this forming operation the apparatus utilized must have suiii-` cient mechanical strength to perform the forming operation and it must be capable of maintaining the shape of the completed joint inclose proximity to the predetermined configuration. These requirements nd their best solution in an apparatus wherein a punch member performs simultaneous shearing and bending operations on a portion of one Wall of a Wave guide tube while the tube is supported interiorly by a die and mandrel. In order to form waveguide joints of the above mentioned type with a high degree of exactness, the punch and die members must be accurately constructed and yet capable of compensating for variations in the wall thickness of the tube stock. The ideal apparatus should be mef. ICC

chanically strong and precisely made and. so constructed as to limit the movement of the punch member to prevent damage to the apparatus.

Therefore, it is an object of this invention to provide an apparatus capable of forming indentations for T-shaped joints in wave guide tubing in a. single forming operation. l

It is another object of this invention to provide an apparatus capable of repeatedly forming indentations in wave guide tubing sections which are all within close tolerances.

lt is a further object of this invention. to provide an apparatus for forming indentations in wave guide tubing sections which is mechanically strong and resistant to forces tending to distort the tubing sections in other than the desired direction.

It is yet another object of the present invention to provide apparatus for simultaneously shearing and forming a wall of a wave guide tube.

In accordance with the above objects, one embodiment of the present invention provides an apparatus comprising a carrier having a hinged cover thereon and slidably mounted in a base for encompassing and supporting the wave guide tubing during the forming operation, a punch member slidably mounted in the carrier and having a forming protuberance thereon, T-slot means to cause the punch member to slide laterally in the carrier and into forming engagement with a wall of the tube as the carrier is sliding parallel to its longitudinal axis in the base, a die having a forming indentaiton therein of the exact conguration desired to be irnparted to the interior surface of the indentation'in the tube wall and of configuration generally complementary to the forming protuberance on the punch member, and a mandrel adapted to back up and support the die during the forming operation and adapted to engage the die upon withdrawal to effect withdrawal of the die from the completed tube section.

Other objects and advantages of the present invention will become apparent from the following detailed description and the accompanying drawings, wherein:

Fig. 1 is a top plan view of the apparatus, partially in section, showing the carrier and punch members in the position which they assume at the completion of the forming step and prior to retraction of the mandrel;

Fig. 2 is a sectional View of the apparatus taken along the line 2 2 of Fig. l;

Fig. 3 is a top plan view of a portion oi the apparatus with the hinged top of the carrier rotated away from the tube showing the pivoted die extractor arm on the end of the mandrel engaging a complementary notch in the die and the carrier in its right-hand position, and in dotted lines the mandrel and die after they have been completely withdrawn from the tube;

Fig. 4 is a perspective view of the carrier showing the punch members and hinge blocks in dotted lines;

Fig. 5 is a sectional View of the apparatus taken along the line 5 5 of Fig. 1;

Fig. 6 is a view similar to Fig.,5 and taken along the line 6-6 of Fig. l;

Fig. 7 is a top plan view of the punch and die members, partially in section, in the relative positions they assume upon completion of the forming operation; p

Fig. 8 is a view illustrating portionsof the punch and die members taken along the line 8--8 of Fig. 7;

Fig. 9 is a top plan View of the tip of the mandrel showing the pivoted die extractor arm thereon;

Fig. 10 is a side elevation view of the tip of the mandrel shown in Fig. 9;

Fig. 1l is a side elevation view of a section of wave guide tubing having a completed indentation formed therein and viewed from the side of engaged and formed' by the punch member;

Fig. 12 is an enlarged sectional view taken along the line 1212 of Fig. ll, and

Fig. 13 is a sectional view taken along the` line 13-13 of Fig. 11.

Attention now is direc-ted to the accompanying drawings, and particularly Figs. 1 to 6, wherein like numerals of reference designate like elements throughout the sev# eral views and wherein there is illustrated'an apparatus for forming indentations in the walls of tubes comprising a base, carrier, and punch assembly, designated generally by the numeral 2t), and a mandrel and die assembly, designated/generally by the numeral 21.

The assembly 20 is constructed of a base 22 having supportingrstrips 23 secured to the bottom thereof by any suitable means (not shown). Slidably positioned in a channel-shaped slideway 24 in the baseV 22 is a carrier designated generally by the numeral 25 (Fig. 4). Thisl carrier is in turn provided with a channel-shaped groovev 26 which isv adapted to receive a section of waveguide tubing 28 to be formed. Centrally located with respect to the ends of the carrier 25 and intersecting a 'lrstside of they groove 26 at right angles is a cut out portion 29 (Fig. 4) adapted 'to receive a tube rpositioning member 30 (Fig. 1). This tube positioning member 30 is secured to carrier 25 by means of screws 31 and is of such configuration that it will secure tube 28 in position when the tube has been inserted .into the tube receiving'groove` 26 so that positioning member 30 projects into a precut` notch 32 (Fig. 12) in tube 2S.

A carrier end member 35 is secured in a cut-away'portion 27 at one end of carrier 25 by means of screws33Y and dowel pins 34 (Fig. 4). This end member 35 is provided with a channel shaped groove 36 which is similar in coniiguration to and axially aligned with groove 26 in the carrier 25, but is of a slightly vreduced cross-section and is adapted to slidably receive the widest portion of a mandrel designated generally by the numeral 38. Also secured in place by means of screws 33 is a first hinge block 39 (Fig. 4) which rests on top of a portion 40 ot" end member 35 that forms one wall of groove 36. A second hinge block 42 is secured by means of screws 43 to the opposite end of carrier 2S and rests on a portion'41 thereof which forms one wall of groove 26 and corre` sponds to portion 40 .of end member 35. Hinge blocks 39 and 42 are provided with al pair of aligned apertures 44 adapted to slidably receive hinge pins 45 which are secured in and project from apertures 46 of carrier cover' plate 48. This arrangement permits cover plate'48 to be rotated about the common axis of the apertures 44'and 46 and hence permits cover plate 48 to be rotatedfout of theway` to permit insertion of a tube section 28 in tube receivinggroove 26 of' carrier 25. Cover plate 48 isfalso provided with a pair of apertures 49 which are adapted to receive' screws 50. These screws are inserted into'apertures 49 and then threaded into apertures51 in carrier 25 to secure the cover plate 48 in a closed position.

Centrally'located with respect to the endsof the carrier 25 and intersecting a second side of the groove 26 at right angles is a slot 52 (Fig. 4) adapted to slidably-receive a punch 53 and a punch holder 54 (both shown in dotted lines in Fig.V 4). The carrier 25 is further provided with a right angle cut-away portion 55 adapted to slidably en'- gagev a vportion of punch actuating member 56'which is secured to base22 by meansr of screws 58. This-punchl actuating member 56 is positioned in av right angle cut away portion 57 of thebase 22,.said cut-away portion being so cut that 'it intersects the slideway-24 of lbase 22. A springcover plate-61 is secured to the extremity of carrier 25, adjacent to the end thereof opposite to: the.

extremity to which end member'35- isy aiixed, by means of screws 59 threaded into apertures 60 therein.

Punch holdingmemberS/t is provided with a T-shaped projection 62 (Fig. 5) which is formed atan angle with the tube which is the longitudinal axis of the holding member. Punch actuating member 56 is provided with a T-shaped slot 63 which is adapted to encompass T-shaped projection 62 in sliding relationship therewith.

The base 22 is provided at one extremity with a spring backing plate 64 which is fixed to the base 22 by means of screws 65. Positioned within the slideway 24, and in abutting relationship with the spring backing plate 64 and an extremity 66 of the carrier 25, are helical springs 68.- Attached to the opposite extremity of the base 22 by means of screws 69 are carrier stops 70 having carrier engaging projectings 71 thereon which are adapted to engage a second extremity 72 of the carrier 25.

The: base 22 and supporting strips 23 are further provided with apertures 73 which are adapted to receive dowel pins (not shown) for the purpose of properly locating the base, carrier, and punch assembly 20 relative to the mandrel and die assembly 21.

Reference will now be made 'to Figs. 7 and 8 wherein is disclosed a die 74 and the punch 53. Die 74 is provided with an inclined longitudinal and transverse notch 75 defined by pointed projections 76. Die 74 is further provided with planar forming surfaces 7S and 79 which deline the linal configuration assumed by the interior wall of the formed indentation of the tube and which are inclined at dieren't angles with respect to the longitudinal axis of the die, for example l5 degrees and 30 degrees, respectively. It is to be understood, however, that these angular values are illustrative only and that the forming section of thel die '74 comprising planar surfaces 78and 79 could be of any configuration which was determined to be necessary or desirable as a result of theoretical calculation.

Punch 53 is provided with angular planar forming surfaces S1 and 82 which are complementary to the planar forming surfaces 7S and '79 of die 74. Punch 53 is also provided with a small projection S3 having a con'- cave surface 54 which is located near the line of intersection of the planes containing planar surfaces 82. The punch is further provided with removable compensating plugs 65 which are positioned in counterbored:

apertures S6. The punch 53 is also provided with projections 38 defined by cut-away portions Sil and which are adapted to engage the L-shaped holding projections S9 (Figs. ll 2 or 3) on the punch holding member 54l 'to-secure the punch member 53 to the punch holding member 54.

Referring now to Figs. l, 2 andv 3 there is shown a mandrel indicated generally by the numeral 38 which is secured at one extremity by a screw 9@ to a mandrel.

adaptor 96. The adaptor 96 is also connected toa shaft 99which, in turn, is connected to a source of reciproeating motion (not shown), such as a double-acting hydraulic or pneumatic cylinder or the like.

The mandrel 3S is provided with its widest portion at its point of connection to the adaptor 96, which widest portion is adapted to be received by the groove 36 in the end member 35. The mandrel 38' is also formed' with a relatively long narrow portion 90 which is integral with the wide portion but which extends in a direction opposite to the point of securement withv the adaptor 96. The portion 96 is formed near the extremity thereof with a bifurcated portion. Pivotally mounted by means of a pivot pin 91 (Figs. 9 and' l0) witlnn the bifurcated extremity of the portion is the leg portion ofa T-shaped die extractor arm 92 which is of such conguration that it can be received in the notch 75Y ofthe die 74 upon withdrawal of the mandrel 38 from the tube. The` pivot pin9il is further provided with a singleturnhelical spring 93 encircling'it and having extended ends 94'and 95 thereon. These spring ends 94: and 95 are adapted to bear against the extremity of the p0rtion 9tlfand;the extractor arm 92, respectively, in suchy amanner that` the extractor arm 92. is resiliently urged4 to rotate in a counter-clockwise direction about the pivot pin 91 as viewed in Fig. 9.

Reference will now be made to Figs. 11, 12 and 13 wherein is disclosed a section of wave guide tubinghaving an angular indentation in one side thereof which is suitable for formng a T-shaped joint in wave guide tubing and which is designated by the reference numeral 28. The tubing section 28 is provided in one side thereof with a cut out notch 32 which extends transversely of the tube and which has a depth equal to the thickness of the wall of the tube and a width equal to the larger transverse dimension of the tube. Within this notch 32 is later secured another section of wave guide tubing (not shown) which forms the upright or leg member of the T-shaped joint. Formed in the wall of the tube 28 which is opposite to the notch 32, and having an axis of symmetry coincident with the axis of sym metry of the notch 32, is an indentation designated generally by the reference numeral 100. The interior boundary of the indentation 100 is defined by inclined planar surfaces 101 and 102 which terminate in a line 108 and which are formed by and hence are complementary to planar forming surfaces 78 and 79, respectively, of die 74. The exterior boundary of the indentation 100 is defined by inclined planar surfaces 103 and 104, angular depressions 105 and a small indentation 106 having at parallel sides and a convex arcuate portion therein. These surfaces Were formed by and hence are complementary to inclined planar surfaces 81 and 82, compensating plugs 85 and projection 83, respec-l tively, of the punch 53. The indentation 100 is integral with the side tube walls at the points 109, but`is only in close engagement with rather than integral with the surfaces 110 and 111, respectively, of the upper and lower tube Walls since the top and bottom of theindentation were sheared away from the upper and lower tube walls along the `lines 112 and 113 (Fig. 1l), respectively, during the forming operation.

In order that a better understanding of the invention may be had, the operation of the apparatus during an indentation forming operation will now be described. The screws 50 are first removed and the hinged carrier cover 48 rotated to its open position to permit access to the tube receiving groove 26 in the carrier 25. A section of wave guide tubing 28 having a precut notch 32 therein is then placed in the tube receiving groove 26 in such a manner that the tube positioning member 30 enters in and engages the sides of the notch 32 thereby accurately positioning the notch 32 relative to the punch 53. In this position the right-hand end of the tube 28 is adjacent the end ofthe groove 36; however, the tube cannot enter the groove 36 since this groove is smaller than the groove 26 and is only of suiiicient size to accommodate the end of the mandrel assembly 21. The carrier cover 48 is then rotated to its closed position and secured in this position by inserting and tightening the screws 50. In this position the bottom surface of the carrier cover 48 is in engagement with the top of the tube 28 (Fig. 5) and thereby serves to restrain and prevent any distortion of the top of the tube during the forming operation. The side andbottom walls of the tube 28 are constrained in a similar manner by the side and bottom walls of the groove 26 in the carrier 25. At this time the carrier 25 is in the position shown in Fig. 3 with the carrier extremity 72 in abutting engagement with the carrier stopping projections 71 as a result of the urging of the compressed springs 68.

Fig. l. lin unison with the mandrel 38 along the groove 36 and i This engagement causes the die "i4 to move into the tube 28. As the die and mandrel assembly 21 continue to move to the left, the extremity 97 of the mandrel adaptor 96 assumes an abutting relationship with the extremity 72 of the carrier 25. The distance fromthe shoulder 37 to the extremity 97 of the adaptor 96 is such that the die 74 will be precisely located' relative to the punch 53 when the extremity 97 engages the carrier extremity 72. Continued leftward movement of the mandrel adaptor will then cause the carrier 25 to move to the left in opposition to the urging of the helical springs 68. As the carrier 25 is forced to the left, the inclined relationship of the T-shaped projection 62 on the punch holding member 54 and the T-shaped slot 63 in the punch actuating member 56 relative to the direction of motion of the carrier 25 will cause the punch 53 and punch holding member 54 to slide transversely of carrier 25 in groove 52.

As the carrier 25 starts moving from the position shown in Fig. 3 to that shown in Fig. l the wall of the tube 28 is rst engaged by the projection 83 on the punch 53. Continued movement of the carrier 25 causes the lateral edges of the various forming surfaces of the punch 53 to shear a portion 100 of the side wall away from the top and bottom walls of the tube along the lines 112 and 113 (Fig. l1) and also causes this por* tion of the tube to be pushed interiorly of the tube by the forming surfaces of the punch. The stroke of the source of reciprocatory movement is adjusted so that movement to the left is terminated when the components reach the positions indicated in Fig. l. When the apparatus cornes to rest this sheared portion 100 of the side wall of the tube has been sandwiched between and hence formed by the punch 53 and die 74.

When the shaft 99 `starts to move to the right, the carrier and punch assembly and the die and mandrel assembly move in unison under the combined inuence of the helical springs 68 and the `source of reciprocatory motion. This combined movement continues until the projections 71 engage the extremity 72 of the carrier 25I and thus prevent further movement of the carrier to the right despite the urging of springs 68. During this -movement of the carrier 25, the sliding engagement of the T-shaped projection 62 on' the punch holding member 54 with the T-shaped slot 63 on the punch actuating member 56 will effect the extraction of the punch 53 from the completed indentation 100 (Fig. 3). As the mandrel 3S continues to move to the right, the die 74 is prevented from moving relative to the tube 28 by the presence of the indentation 100 adjacent the forming surfaces of the die and therefore the tip of the mandrel 38 starts to slide along the surface 87 (Fig. 3) of the die. This relative movement continues until the extremity of the tip 90 has just passed the plane of the surface77 of the die. At this -time the extractor arm 92 is aligned with the notch 75 in the die and the single coil spring 93 causes the extractor arm 92 to rotate counterclockwise and into engagement with the notch 75. As the mandrel 38 continues to withdraw, the extractor arm 92 will pull the die 74 out of the tube. The maximum width of the die 74 is such that it will pass between the corner 108 of the formed indentation 100 and the tube positioning member 30. The screws 50l are then removed, the carrier cover 48 rotated away, and the completed Wave guide joint member removed from the carrier.

The exact conguration of the projection 83 on the punch 53 is determined empirically and may vary to some extent. Its prime requisite is that the configuration be such that it will cause the metal of which the tube wall is composed to cold flow into the corner formed by the planar forming surfaces 79 (Fig. 7) on the die 74 so that a sharp corner 108 (Fig. 12) is formed. This corner 108 is very important and must be precisely formed. The compensation plugs 85v are inserted in the punch 53 to prevent the formation of dimples along the line of intersection of the surfaces 101 and 102 of the indentation 100. They are made removable so that different compensating plugs of various heights may be inserted to provide more or less compensation as may be found to be necessary.

Thisapparatus combines the advantages of the strength, rigidity, and accuracy necessary to effect the formation of indentations in the wall of a tube with ease of assembly and disassembly of the punch and die mechanism to permit insertion of various punch and die sets. Thus the apparatus can be readily adapted to form indentations of varying congurations.

Further, this apparatus can readily be adapted to form openings in tube walls instead of indentations. This feature is desirable when making wave guide joints. of types other than the one disclosed herein.

lt is to be understood that various additions or modifications could be made to the embodiment disclosed herein by those skilled in the art to achieve a similar apparatus which is within the spirit and scope of the present invention.

What is claimed is:

l. A punch and die mechanism for shearing and forming indentations in the walls of rectangular tubes comprising a punch for shearing and forming the exterior of :an indentation in a wall of a tube, said, punch having` shearing edges and forming surfaces thereon, a die for forming the interior of said indentation, a mandrel for supporting said die and then extracting said die .from said tube, and a lost motion connection between said punchY and said mandrel for actuating said punch while the mandrel supports said die.

2. An apparatus for forming indentations in the walls of tubes comprising a base, tube receiving means slidably mounted in said base, exterior forming means slidably mounted in said tube receiving means, means attached to said base and in sliding engagement with said exterior forming means whereby said exterior forming means is actuated when said tube receiving means is moved relative to said base, interior forming means, and meansk for supporting and then extracting said interior forming means.

3. A punch and die mechanism for forming indentations in the walls of rectangular tubes comprising a base, a tube holding carriers slidably mounted in said base, a punch slidably mounted in said carrier for forming the exterior of an indentation in a wall of a tube, :a punch actuating member attached to said base and in sliding engagement with said punch whereby said punch is caused to slide relative to said carrier and into or away from forming engagement with said tube when said carrier is moved relative to said base, a die for forming the interior of the indentation, and a mandrel for supporting, and then extracting said die.

4. A punch and die mechanism for shearing Iand forming indentations in the walls of. rectangular tubes cornprising. a base, a tube holding carrier slidably mounted in said base, .a punch slidably mounted in said carrier for shearing and forming the exterior of an indentation in a wall of a tube, said punch being provided with shearing edges and forming surfaces, a punch actuating member attached to said base and in sliding engagement with said punch whereby said punch is caused to slide relative to said carrier and into or away from shearing and forming engagement with said tube when said carrier is moved relative to said base, a die for forming the interior of the indentation, and a mandrel for supporting said die and then extracting said die from said tube.

5. An apparatus for forming indentations in the wallsl of tubes comprising a base, tub-e holding means slidably mounted in said base, exterior tube. forming meansV mounted' in said tube holding means and slidable transversely thereof at right angles thereto, means attached to" lsaid base and in sliding engagement with said exterior tubeforming means whereby said exterior tubeV forming means is moved transversely of and at right angles to said tube holding means when said tube holding means is moved relative to said base, interior tube formingy means, and means for supporting and then extracting said interior tube forming. means.

6. A punch andY die mechanism for forming indentations in the walls of rectangular tubes comprising a base, a tube receiving carrier slidably mounted in said base, a punch for forming the exterior of an indentation in a wall of a tube mounted in said carrier and slidable transversely thereof at right angles thereto, a punch actuating member attached to said base and in sliding engagement with said punch whereby said punch is caused to slide transversely of and at right angles to said carrier and into or away from forming engagement with said tube when said carrier is moved relative to said base, a die for forming the interior of the indentation, and a mandrel for supporting and then extracting saiddie.

7. A punch and die mechanism for shearing and forming, indentations in the walls of rectangular tubes comprising a base, a tube holding carrier slidably mounted in said base, a punch 'for shearing and forming the exterior of an indentation in a wall of a tube mounted in said carrier and slidable transversely thereof at right angles thereto, said' punch having shearing edges and forming surfaces thereon, a punch actuating member secured to said baseV and in sliding engagement with said punch whereby said punchis caused to slide transversely of and at right angles to said carrier and into or away from shearing and forming engagement with said tube when said carrier is moved relative to said base, a die for forming the interior ofthe indentation, and a mandrel for supporting said die and then extracting said die from said tube.

8L An apparatus for forming indentations in the walls of tubes comprising a base, tube receiving means slidably mounted in said base, exterior tube forming means slidably mounted in said tube receiving means, means attached to said base and in sliding engagement with said exterior tube forming means whereby said exterior tube forming means is actuated when said tube receiving means is moved relative to saidbase, interior tube forming means, supporting means having a lirst extremity thereof adapted to support the interior tube forming means during the forming operationand adapted to engage the interior tube forming. means upon withdrawal whereby the supporting. means engages-the interior tube forming means as the supporting. means is withdrawn from its supporting position and thereby effects the withdrawal of the interior tube formingy means, and reciprocable means secured to a second extremity of said supporting means and adapted to insert into and withdraw from a tube being formed said supporting means and said interior tube forming means.

9. A punch and die mechanism for forming indentations in the walls of rectangular tubes comprising a base, atube holding carrier slidably mounted in said base, a punch slidably mounted in said carrier for forming the exterior ofan indentation in a wall of a tube, -a punch actuating member attached to -said base and in sliding engagement with said punch whereby said punch is caused to slide relative to said carrier and into or away from forming engagement with said tube when said carrier is movedk relative to said base, a die for forming the interior ofthev indentation, a mandrel having a first extremity thereof adapted to support the die during the forming operation", and adapted to engage the die upon withdrawal from its supporting position whereby the mandrel engages' the die as the mandrel is withdrawn from its supporting position and thereby effects withdrawal of the die, and reciprocable means secured to aY second extremity of said mandreland adapted to insert into and withdraw from a tubefbeing formed saidmandrel and said'die.

10.2 A pun'cbtand4 die mechanism for shearing and forming indentations in the walls of rectangular tubes comprising a base, a tube holding carrier slidably mounted in said base, a punch slidably mounted in said carrier for shearing and forming the exterior of an indentation in a wall of a tube, said punch being provided with shearing edges and forming surfaces, a punch actuating member secured to said base and in sliding engagement with said punch whereby said punch is caused to slide relative to said carrier and into or away from shearing and forming engagement with said tube when said carrier is moved relative to said base, a die for forming the interior of said indentations, a mandrel having a first extremity thereof adapted to support the die during the shearing and forming operation and adapted to engage the die upon withdrawal from its supporting position whereby the mandrel engages the die as the mandrel is withdrawn from its supporting position and thereby effects withdrawal of the die, and reciprocable means secured to a second extremity of said mandrel and adapted to insert into and extract from a tube being sheared and formed said mandrel and said die.

l1. A punch and die mechanism for shearing and forming indentations in the walls of rectangular wave guide tubes comprising a base, a tube supporting carrier having a tube receiving groove therein slidably mounted in a slideway in said base, a spring stop secured to a rst extremity of said base, resilient springspositioned in the slideway in said base and abutting said spring stop and a first extremity of said carrier and urging said carrier along the slideway toward a second extremity of said base, carrier stops secured to said second extremity of said base and adapted to engage a second extremity of -said carrier and thereby limit to a predetermined amount the sliding movement of said carrier under the influence of said springs, a shearing and forming punch mounted in said carrier and adapted to slide transversely thereof, a first extremity of said punch being provided with shearing edges and forming surfaces generally complementary to the exterior configuration of an indentation to be formed in a wall of a tube, a punch holder secured by a first extremity thereof to a second extremity of said punch, said punch holder being provided 10 with a projection on a second extremity thereof which is inclined at an acute angle to the parallel longitudinal axes of said carrier and said punch holder, a punch actuating member secured to said base and provided with an inclined recess parallel to and in sliding engagement with the inclined projection on said punch holder whereby said punch is caused to slide transversely of said carrier and into or away from shearing and forming engagement with said tube as said carrier slides relative to said base, a die for forming the interior of said indentation in said tube, said die being provided with depressed forming surfaces of the conguration desired to be imparted to the interior surfaces of said indentation, said die being further provided with an engaging notch in a corner of said die which is opposite to said depressed forming surfaces, a mandrel for inserting said die into said tube and then supporting said die during the shearing and forming operation, said mandrel having a rst extremity thereof adapted to abut the two sides of said die which form the corne-r wherein is 1ocated said engaging notch, said first extremity of said mandrel being further provided at the tip thereof with a pivotally mounted spring-biased die extractor arm which is adapted to be urged into engagement with said notch in said die upon withdrawal of said mandrel from said tube thereby effecting withdrawal of said die from said tube as said mandrel is withdrawn from said tube, and means f for providing reciprocatory movement secured to a second extremity of said mandrel whereby said mandrel and said die are inserted into said tube prior to said shearing and forming operation and said mandrel and said die are extracted from said tube subsequent to said shearing and forming operation.

References Cited in the le of this patent 

